Hi, I have a Canon G10 and have a particular situation where I need to use a remote flash gun but I cannot use the internal flash. My understanding is that the main flash (internal) normally triggers the remote flash but is there a way of getting round this??

The situation I have is that I am using a "one shot lens" which is actally a mirror that captures a 360 image around the room. I cannot use the internal flash as that would fire directly at the mirror and completely blast out anything reflected in the mirror. So my idea was to use an external flash and set it up on a tripod so that I could take a shot and compensate for excessive light coming through a window. Then I can take an under exposed shot to reveal the view out of the window and then merge the two images in my photo editing suite.

I have a few flash guns which I bought on the cheap but when I put them in the hotshoe the Internal flash still works in tandem.

I cannot see any other way of doing this apart from taking an initial shot with some screening over the window to reduce the light.

...I have a few flash guns which I bought on the cheap but when I put them in the hotshoe the Internal flash still works in tandem.

Be careful if you don't want to damage your camera. Canon models are designed for low trigger voltages from hot shoe attached flashes, and some flashes may be using very high trigger voltages that could damage the camera's electronics. See this thread:

It's my understanding that the internal flash is disabled automatically when using a compatible hot shoe attached flash. But, with a generic (versus dedicated) flash, the camera may not be seeing what it needs on the proprietary hotshoe contacts.

Chances are, some of the available radio triggers that use the extra contacts could get around that problem. But, you'd have to dig around for user reports to see how they work with a given camera. Here's one article I found mentioning using a Yongnuo RF-602 with a G9. Sets with a transmitter, receiver and batteries tend to run as low as $31 delivered from vendors in China, and around $59 delivered from vendors in Hong Kong. Just search on Ebay for RF-602 and you'll find some listings for them (note that you'll want a Canon Specific model as they make more than one). But, I have no experience with them and don't know if you'd see any issues with a G10.

Pocket Wizards are considered to be very good as compared to the more generic triggers (as unlike the cheaper triggers, they'll also work with dedicated flash models and support TTL modes). But, they're pricey in comparison: